Thermostatic circuit-breaker.



N. BENDIXENJD THERMOSTATIC CIRCUIT BREAKER. APPUCATION FILED SEPf.5. 1914-- RENEWED IAN. 2.1917.

1 ,233,74;6. Patented July 17, 1917.

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. Affornegs.

UNITED STATES PATENT OFFICE.

NInLs BENDIXEN. or COPENHAGEN, DENMARK.

THERMOSTATIC CIRCUIT-BREAKER.

Specification of Letters Patent P t t July 7 7 Application filed September 5, 1914,-Seria1'No. 860,475. Renewed January 2, 1917; Serial Nor 140,308.

Toall whom it may concern;

Be it known that I, NInLs BENDIXEN, a subject of the Kingdomof Denmark, residing at Copenhagen, Nr..,31, Gamle Kongevej,

Denmark, have invented certain new and useful Improvements in Thermostatic Circuit Brealcers', andespecially in devices of that nature actuated y expansion of fluid against yielding diaphragms having electric contacts arranged to move therewith.

The chief object of said invention is to provide satisfactory means for. closing or opening circuit and thereby sounding an alarm' when thereis a sudden rise in temperature, also when thereis a slow and gradu'alrise. To this end I'employ an uninclosed liquid-containing receptacle, also aninclosed one, the former being the more ex posed and therefore more immediately responsive" to sudden change, i The electric current follows'difierent paths through the apparatusjn the two cases, although one of the contacts and its supporting spring-arm is utilized for both.

The accompanying drawing represents a vertical central section through the apparatus, some of the parts being shown in side elevation;

To the insulating base 1 are fastened two tubular studs Zand 3; supporting above said base two receptacles 4 and 5, having pref-' erably the dish-form shown in said drawings and supplied with expansible fluid through the'bores of said studs. This fluidmay be normally liquid, e .anding into a.

vaporous condition when su ciently heated.

For example itmay be sulfuric ether or acetaldehyde. Each of said receptaclesis provided with a yielding diaphragm 6 or 7, preferably stretched over the top of the some and subject on one side to the expansive action of said fiuid and on the other side to the pressure of the atmosphere.

In the center of the diaphragmfi is ar-' ranged a pin 8 which in the end opposite to the said diaphragm is provided with a reduced extension 10, which is inserted in a hole'in a U-shaped spring 12. The dia phragm 7 carries at its center a firmly connected pin 9, the upper end of which is pro- .vided with two bifurcations 11 and 11*,

between contacts 14 and 15, is electrically connected with the stud Around the receptacle 5 is placed a case 18 with openings 19 and '20 respectively in the top and bottom thereof.

The tubular studs 2- and 3, after the receptacles 4 and 5 have been filled through the same are closed by means of plugs and s0ldered. The said studs are connected with the two poles and of an electrical circuit, which includes a generator and an alarm.

This circuit closer is operated by a slight sudden rise of temperature; also by a slow and greater rise of temperature.

By a. swift rise of the temperature th fluid in the receptacle 4 is vaporized, whereby the pressure of the vapor acts upon the diaphragm 6, the pin 8 and one end of the spring 12, so that the latter moves up ward. The contact '14 thereby will come in touch with contact 15 and close an electrical circuit through the wire 22, the stud 2, the spring 12, the contacts 14 and 15, the spring 13, the stud Sand the wire 23, thereby operating the alarm-bell or the like, which is inserted in the circuit.

The fluid in the receptacle 5 is only slightly influenced by the rise of the temperature, because this receptacle is protected by. the case 18, so that the spring 13 and the contact 15 remain in' almost unaltered position. By a slow rise of the temperature th receptacle 5 will be heated almost as swiftlyas the receptacle 4:, the air circulating through the openings 19 and 20. The con tacts 14 and 15 will therefore both move upward, but without touching each other. WVhen the rise of the temperature has reached a certain height, the contact 15 will touch the screw 17, and a circuit is then closed through the wire 22, the'stud 2, the

rod 16, the screw 17, the contact 15, the

spring 13, the stud 3 and the wire 23.

Of considerable importance to the invention it the particular shape of the pin 9 with its two bifurcations 11 and 11' and the manner in which the latter act upon the spring 13.

lVhen the spring 13 is in its central p0sitiona-s shown in the drawing'it is touched by both bifurcations 11 and 11 If the temperature rises, so that the spring 13 is moved upward, it isonly touched by the bifurcation 11, and the speed of. the contact 15 is thereby increased. If the temperature is lowered, so that the spring 13 moves downward, the arm of the lever is altered, sothat the speedni the contact 15 decreases. This arrangement is very advantageous for preventing errors which may arise on account of the diaphragms not bein manu factured moving with the same speed.

' Having now particularlydescribed. and ascertained thenature of my said invention, I declare that what I claim is:

1. A pair of expansihle receptacles for fluid, in combination with a casin sur-. rounding one of them, contacts carried by said receptacles respectively and arranged to control the circuit-bythe greater responsiveness. of the uninclosed receptacle to sudden increase of temperature, an additional relatively fixed, contact arranged to cooperate with the contact. carried by the inclosed receptacle for'controlling the circuit when a gradual increase of heat 'is operative on the receptacle, without closing the circuit throu h the contacts carried by the two receptac les as first above stated.

2. A pair-of fluid-containing ending "receptacles, one of inclosed m-Ia prouite similarly and there ore not tcctive casing, the other being left open to the. sudden action of increased temperature, contacts carried by said receptacles and arranged to close a circuit by the expansion of the latter receptacle while the former receptaclc.rcmains substantially without expansion, and an additional contact arranged to close circuit through the contact carried by the inclosed receptacle when thetwo receptacles expand to a certain degree under gradual rise of'temperature without their contacts coming into touch with each other.

3. A pair of receptacles for fluid provided with expansible diaphragms, in combination with tubular, electrically conducting studs for supporting and supplying such receptacles, pi carried by said diaphragms, a casing sur fnding one of mid receptacles and partially.- )notecting it against heat, contacts carried b said pins, and arranged one above theother, electric connections from said contacts to said studs, circuit wires connected to the latter, an additional contact arranged to coiiperate with the contact carried by said inclosed receptacle and electric connections between this latter contact and the stud supportin the other receptacle, in order that a, gm ual increase of heat to a cer tain point may close the circuit through the latter contact, though asudden increase of heat will close circuit throu h the two contacts carried by the receptac es. 1

. In witness whereof I have hereunto set my hand in the presence of a witness.

' I NIELS BENDIXEN. Witness:

Yacnus JENSEN. 

